[citation needed] On 16 December 1916, four under construction in the Reiherstieg and Flensburger Schiffbau yards were taken over by the navy and converted to military specification as Type U 151 U-boats, being designated U-151 to U-154.

[3] Deutschland made two successful commercial voyages before being commissioned into the Kaiserliche Marine on February 17, 1917, as U-155.

[citation needed] Max Valentiner commanded a Type U 151 U-boat, U-157, and undertook the longest cruise in the war from 27 November 1917 to 15 April 1918, a total of 139 days.

High-scoring Waldemar Kophamel also commanded a Type U 151 U-boat, U-151 in late summer and fall of 1917.

[citation needed] Seven Type U 151 submarines were built, of which six were commissioned into the Kaiserliche Marine.